It is known that stored thermal energy may be employed to reduce exhaust emission pollutants from an internal combustion engine by facilitating engine warm-up. Stored thermal energy may also be provided to the engine to minimize engine warm-up time and reduce cold start engine-wear, thereby increasing engine durability. Further, the more rapidly the engine is heated, the quicker the engine will operate at increased efficiencies to improve fuel consumption characteristics.
The broad concept of the utilization of thermal energy storage systems for internal combustion engines employing a thermal energy storage device capable of efficiently supplying thermal energy from the thermal energy storage device to an internal combustion engine is disclosed in a paper entitled Development of New Generation Hybrid System identified as SAE Technical Paper Series 2004-02-0643, hereby incorporated herein by reference in its entirety.
Automotive vehicle emissions, fuel economy, and power train durability are heavily influenced by warming conditions during engine start-up. To enhance engine warming conditions, thermal energy storage devices have been developed to store a gas or liquid medium at high normal operating temperatures. Many of such systems employ a phase change material (PCM) that has been exposed to a solid-liquid or liquid-gas phase change heat of fusion to optimize the latent heat energy storage thermal capacity of the associated working medium. The phase change materials currently used are typically corrosive and when used with working medium result in significant additional vehicle cost and space requirements.
It is therefore considered desirable to produce a thermal energy recovery and management system for an internal combustion engine which stores a heated working medium in a insulated bottle which is released into the internal combustion engine operating system to minimize emissions in an exhaust gas from unburned hydrocarbons, maximize fuel efficiency, and minimize engine wear, especially during cold start conditions.